The Problem of Modular Hip Endoprosthesis

Avtorji

Drago Dolinar
Department for Orthopaedic Surgery, University Medical Centre Ljubljana, Ljubljana, Slovenia and Medical Faculty, Chair for Orthopaedic Surgery, University of Ljubljana, Ljubljana, Slovenia and MD-RI Institute for Materials Research in Medicine, Ljubljana, Slovenia
Igor Potparič
Department for Orthopaedic Surgery, University Medical Centre Ljubljana, Ljubljana, Slovenia and Medical Faculty, Chair for Orthopaedic Surgery, University of Ljubljana, Ljubljana, Slovenia
Monika Jenko
MD-RI Institute for Materials Research in Medicine, Ljubljana, Slovenia
Mojca Debeljak
Faculty of Polymer Technology, Slovenj Gradec, Slovenia and Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia

Kratka vsebina

The mechanisms of premature fracture of modular-neck stems in two case studies: (I) when the neck and stem are both made of the same Ti6Al4V alloy, and (II) when the neck and stem are made from two different alloys, CoCrMo and Ti6Al4V alloy are presented. The study integrates two orthopedic patients who have undergone primary uncemented THA for usual indications in two orthopedic centers). Both centers are part of the national public health care system. Both surgeries were performed by two skilled orthopedic surgeons with more than 10 years of experience in THA. The survivorship of the modular neck of cast CoCrMo alloy was 24 months. The survivorship of the modular neck from Ti6Al4V alloy was 84 months. Advanced analyses were performed to assess the differences in the fretting, corrosion, and fatigue, using stereo light microscopy (SLM), scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS), and electron backscatter diffraction (EBSD). Patient demographic information, including sex, age, body mass index, survivorship of implants, and reason for the revision, was collected from medical records. The fretting and fatigue occurred on both modular stem retrievals, but the CoCrMo/Ti6Al4V alloy system suffered more corrosion due to additional galvanic corrosion and fractured earlier than the Ti6Al4V/Ti6Al4V metal alloy system. Bothmetallic alloy systems used in this application are known to be highly corrosion-resistant, but the bio-tribo-corrosion processes need to be understood in detail and characterized so that appropriate improvements in design and materials can be made.

Prenosi

Izdano

6 March 2025

Kako citirati

Dolinar, D., Potparič, I., Jenko, M., & Debeljak, M. (2025). The Problem of Modular Hip Endoprosthesis. In Y. Istileulova (Ed.), Socratic Lectures 12th International Symposium, Ljubljana, 11. January, 2025: PART I (pp. 41-45). Založba Univerze v Ljubljani. https://doi.org/10.55295/PSL.12.2025.I5